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The influence of the leading-edge angle of subgrade on the aerodynamic loads of a high-speed train in a wind tunnel

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Transportation Safety and Environment 2024年第2期6卷 45-54页

作者： Zeyun yang gang Xu Fan Wu Lei Zhang jian Du Dmitri Vainchtein Key Labor atory of Traffic Safety on Track Ministry of EducationSchool of Traffic&Transportation EngineeringCentral South UniversityChangsha 410075HunanChina CRRC Academy(Qingdao)Co. Ltd.Qingdao 266111ShandongChina CRRC Qingdao Sifang Co. Ltd.Qingdao 266111ShandongChina Nyheim Plasma Institute Drexel UniversityCamden 08103USA

The purpose of this study is to establish the correlation between the boundary layer over the subgrade and the aerodynamic loads act-ing on the train model in conventional wind tunnel tests.Firstly,flow characteristics around the subgrade with different leading-edge angles(15°,30°and 45°)are investigated through the particle image velocimetry(PIV)experimental test method.Then,wind tunnel tests of the aerodynamic performance of a high-speed train are carried out.The results are compared with previous experimental data obtained by moving model tests.Results show that,due to the presence of a boundary layer,the pressure acting on the lower part of the train head decreases,while other locations are not significantly affected.This is the reason for the reduction of the aerodynamic drag and lift on the train.In addition,the reduction effects become more obvious when the thickness of the boundary layer increases.The experimental results obtained could serve as a calibration of aerodynamic forces for wind tunnel tests on high-speed trains.

关键词： high-speed train ground effect aerodynamic performance wind tunnel test PIV experiment

Efficacy of scraping therapy on blood pressure and sleep quality in stage Ⅰ and Ⅱ essential hypertension: A systematic review and meta-analysis

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Journal of Integrative Medicine 2024年第1期22卷 12-21页

作者： Zheng-gang Zhu jian-ru Wang Xiao-yan Pan School of Nursing Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina School of Health Sciences Universiti Sains MalaysiaKubang Kerian 16150KelantanMalaysia Department of Cardiovascular Medicine the First Affiliated Hospital of Henan University of Chinese MedicineZhengzhou 450000Henan ProvinceChina

Background Scraping therapy is widely used in treating stage I and II essential hypertension in China.However,there has been no systematic evaluation of the efficacy of scraping therapy on blood pressure and sleep quality in stage I and II essential hypertension.Search strategy Seven electronic databases(PubMed,Scopus,Cochrane Library,Web of Science,EBSCO,China National Knowledge Infrastructure and Wanfang Data electronic databases)were searched from inception to December 2022.Based on the principle of combining subject words with text words,the search strategy was constructed around search terms for“scraping therapy,”“scraping,”“Guasha,”“Gua sha,”“hypertension,”and“high blood pressure”during the database searches.Inclusion criteria Randomized controlled trials(RCTs)were included if they recruited patients with stage I and II essential hypertension and included a scraping therapy intervention.The intervention group received antihypertensive drugs and scraping therapy,while the control group only took antihypertensive drugs.Data extraction and analysis Review Manager 5.4.0 and STATA 15.1 were used to enter all the relevant outcome variables to conduct the meta-analysis.The quality of the selected RCTs was assessed using the PEDro scale.The sensitivity analysis was carried out by iteratively excluding individual studies and repeating the analysis to determine the stability of the findings and identify any studies with greater influence on the outcome.Subgroup analysis was performed to find the source of heterogeneity.Funnel plots were used to evaluate the publication bias of included studies.Results Nine RCTs including 765 participants were selected.Meta-analysis showed that scraping therapy combined with medication had an advantage over the use of medication alone in lowering systolic blood pressure(mean difference[MD]=?5.09,95%confidence interval[CI]=?6.50 to?3.67,P<0.001)and diastolic blood pressure(MD=?2.66,95%CI=?3.17 to?2.14,P<0.001).Subgroup analysis showed that scraping therapy improved sleep quality in mid

关键词： Scraping therapy Essential hypertension Efficacy Blood pressure Sleep quality Systematic review Meta-analysis

Nanophononic metamaterials induced proximity effect in heat flux regulation

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Frontiers of physics 2024年第2期19卷 149-156页

作者： jian Zhang Haochun Zhang gang Zhang School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China Institute of High Performance Computing Agency for ScienceTechnology and Research(A*STAR)Singapore 138632Singapore

Recent studies have shown that the construction of nanophononic metamaterials can reduce thermal conductivity without affecting electrical properties,making them promising in many fields of application,such as energy conversion and thermal management.However,although extensive studies have been carried out on thermal conductivity reduction in nanophononic metamaterials,the local heat flux characteristic is still unclear.In this work,we construct a heat flux regulator which includes a silicon nanofilm with silicon pillars.The regulator has remarkable heat flux regulation ability,and various impacts on the regulation ability are explored.Surprisingly,even in the region without nanopillars,the local heat current is still lower than that in pristine silicon nanofilms,reduced by the neighboring nanopillars through the thermal proximity effect.We combine the analysis of the phonon participation ratio with the intensity of localized phonon modes to provide a clear explanation.Our findings not only provide insights into the mechanisms of heat flux regulation by nanophononic metamaterials,but also will open up new research directions to control local heat flux for a broad range of applications,including heat management,thermoelectric energy conversion,thermal cloak,and thermal concentrator.

关键词： nanophononic metamaterials proximity effect

Correlation between serum markers and transjugular intrahepatic portosystemic shunt prognosis in patients with cirrhotic ascites

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World Journal of Gastrointestinal Surgery 2024年第2期16卷 481-490页

作者： Xiao-gang Hu Xiao-Xian yang Jun Lu gang Li jian-Ji Dai Jia-Min Wang Yi Deng Rui Feng Department of Interventional Radiology The Affiliated Jinhua HospitalZhejiang University School of MedicineJinhua 321000Zhejiang ProvinceChina Medical College Jinhua PolytechnicJinhua 321017Zhejiang ProvinceChina Department of Interventional Medicine Zhejiang Provincial People’s HospitalPeople’s Hospital of Hangzhou Medical CollegeHangzhou 310000Zhejiang ProvinceChina

BACKGROUND Individuals with refractory ascites in the context of liver cirrhosis typically face an adverse prognosis.The transjugular intrahepatic portosystemic shunt(TIPS)is an efficacious intervention,but there is a lack of reliable tools for postoperative pro-gnosis assessment.Previously utilized clinical biochemical markers,such as the serum albumin concentration(Alb),sodium(Na+)concentration,and serum creatinine(Scr),have limited predictive value.Therefore,the quest for novel,specific biomarkers to evaluate the post-TIPS prognosis in patients with liver cirrhosis and refractory ascites holds significant practical importance.A retrospective analysis was conducted on 75 patients with liver cirrhosis and refractory ascites who underwent TIPS at our institution from August 2019 to August 2021.These patients were followed up regularly for two years,and the death toll was meticulously documented.The patients were allocated into a survival group(n=45 patients)or a deceased group(n=30 patients)based on their prognosis status.The clinical data of the two groups were collected,and Child-Pugh scores and MELD scores were calculated for analysis.Spearman correlation analysis was carried out to evaluate the correlation of prognosis with Child-Pugh grade,MELD score,and Cys C level.Additionally,a multiple-factor analysis utilizing the Cox proportional hazard model was used to identify independent risk factors affecting the post-TIPS prognosis of patients with liver cirrhosis and refractory ascites.The receiver operating characteristic curve(ROC)ascertained the predictive value of the Cys C concen-tration,Child-Pugh grade,and MELD score for the prognosis of liver cirrhosis with refractory ascites in post-TIPS patients.RESULTS During a 2-year follow-up period,among 75 patients with liver cirrhosis and refractory ascites who underwent TIPS treatment,30 patients(40.00%)passed away.The deceased cohort exhibited heightened aspartate aminotrans-ferase,alanine aminotransferase,total bilirubin,Scr,prothrombin time,Cys C,internationa

关键词： Liver cirrhosis Refractory ascites Transjugular intrahepatic portosystemic shunt Cystatin C

What benefit can be obtained from magnetic resonance imaging diagnosis with artificial intelligence in prostate cancer compared with clinical assessments?

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Military Medical Research 2024年第2期11卷 268-286页

作者： Li-Tao Zhao Zhen-Yu Liu Wan-Fang Xie Li-Zhi Shao jian Lu Jie Tian jian-gang Liu School of Engineering Medicine Beihang UniversityBeijing 100191China School of Biological Science and Medical Engineering Beihang UniversityBeijing 100191China CAS Key Laboratory of Molecular Imaging Institute of AutomationBeijing 100190China University of Chinese Academy of Sciences Beijing 100080China Department of Urology Peking University Third HospitalPeking UniversityBeijing 100191China Key Laboratory of Big Data‑Based Precision Medicine(Beihang University) Ministry of Industry and Information Technology of the People's Republic of ChinaBeijing 100191China Beijing Engineering Research Center of Cardiovascular Wisdom Diagnosis and Treatment Beijing 100029China

The present study aimed to explore the potential of artificial intelligence(AI)methodology based on magnetic resonance(MR)images to aid in the management of prostate cancer(PCa).To this end,we reviewed and summarized the studies comparing the diagnostic and predictive performance for PCa between AI and common clinical assessment methods based on MR images and/or clinical characteristics,thereby investigating whether AI methods are generally superior to common clinical assessment methods for the diagnosis and prediction fields of PCa.First,we found that,in the included studies of the present study,AI methods were generally equal to or better than the clinical assessment methods for the risk assessment of PCa,such as risk stratification of prostate lesions and the prediction of therapeutic outcomes or PCa progression.In particular,for the diagnosis of clinically significant PCa,the AI methods achieved a higher summary receiver operator characteristic curve(SROC-AUC)than that of the clinical assessment methods(0.87 vs.0.82).For the prediction of adverse pathology,the AI methods also achieved a higher SROC-AUC than that of the clinical assessment methods(0.86 vs.0.75).Second,as revealed by the radiomics quality score(RQS),the studies included in the present study presented a relatively high total average RQS of 15.2(11.0–20.0).Further,the scores of the individual RQS elements implied that the AI models in these studies were constructed with relatively perfect and standard radiomics processes,but the exact generalizability and clinical practicality of the AI models should be further validated using higher levels of evidence,such as prospective studies and open-testing datasets.

关键词： Clinically significant prostate cancer Adverse pathology Radiomics quality score Artificial intelligence Magnetic resonance imaging

Diagnostic performance of intravascular ultrasound-based fractional flow reserve in evaluating of intermediate left main stenosis

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Journal of Geriatric Cardiology 2024年第1期21卷 34-43页

作者： Yong-gang SUI Cheng yang Chang-Dong GUAN Yan-Lu XU Na-Qiong WU Wei-Xian yang Yong-jian WU Ke-Fei DOU Yue-Jin yang Shu-Bin QIAO Wei YU Bo XU Sheng-Xian TU Jie QIAN Department of Cardiology Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina Catheterization Laboratories Fuwai HospitalNational Center for Cardiovascular DiseasesChinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina Biomedical Instrument Institute School of Biomedical EngineeringShanghai Jiao Tong UniversityShanghaiChina National Clinical Research Center for Cardiovascular Diseases BeijingChina

BACKGROUND The recently introduced ultrasonic flow ratio(UFR),is a novel fast computational method to derive fractional flow reserve(FFR)from intravascular ultrasound(IVUS)images.In the present study,we evaluate the diagnostic performance of UFR in patients with intermediate left main(LM)stenosis.METHODS This is a prospective,single center study enrolling consecutive patients with presence of intermediated LM lesions(diameter stenosis of 30%-80%by visual estimation)underwent IVUS and FFR measurement.An independent core laboratory assessed offline UFR and IVUS-derived minimal lumen area(MLA)in a blinded fashion.RESULTS Both UFR and FFR were successfully achieved in 41 LM patients(mean age,62.0±9.9 years,46.3%diabetes).An acceptable correlation between UFR and FFR was identified(r=0.688,P50%(AUC=0.66,P<0.001)and numerically higher than IVUS-derived MLA(AUC=0.82;P=0.09).Patient level diagnostic accuracy,sensitivity and specificity for UFR to identify FFR≤0.80 was 82.9%(95%CI:70.2-95.7),93.1%(95%CI:82.2-100.0),58.3%(95%CI:26.3-90.4),respectively.CONCLUSION In patients with intermediate LM diseases,UFR was proved to be associated with acceptable correlation and high accuracy with pressure wire-based FFR as standard reference.The present study supports the use of UFR for functional evaluation of intermediate LM stenosis.

关键词： stenosis flow fractional

Liquid-phase epitaxial layer by layer brushing fabrication of metalorganic frameworks films

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Nano Research 2024年第6期17卷 5698-5704页

作者： Li-Mei Chang Rui Zhai Zhi-Zhou Ma jian-Dong Huang Zhi-gang Gu jian Zhang College of Chemistry Fuzhou UniversityFuzhou 350108China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China University of Chinese Academy of Sciences Beijing 100049China

Development of metal-organic framework(MOF)films is of great importance to expand their applications.Herein,we report a facile and universal method of liquid-phase epitaxial(LPE)layer by layer(LBL)brushing approach for fabricating MOF films on various substrates in a high-throughput fashion.This MOF films preparation method offers a great prospective to cost-effectively construct films with short preparation time and little reagent consumption.Moreover,this LBL brushing approach has been implemented successfully to assemble various MOF films,including HKUST-1,zeolitic imidazolate framework-8(ZIF-8),Cu(bdc),and Cu_(2)(L)_(2)P(L=bdc,ndc,and cam;P=dabco and bipy).Afterwards,the classic MOF HKUST-1 and ZIF-8 films were grown on sensor chip electrode and porous fiber support for good volatile organic compounds(VOCs)selective sensing and water purification applications.This study demonstrates that this LBL brushing preparation method can be employed to synthesize various MOF films with a variety of characteristics to realize their sensing and separation applications.

关键词： metal-organic framework porous materials layer by layer fabrication film

Urban rail transit disruption management: Research progress and future directions

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Frontiers of Engineering Management 2024年第1期11卷 79-91页

作者： Lebing WANG jian gang JIN Lijun SUN Der-Horng LEE School of Naval Architecture Ocean&Civil Engineeringand State Key Laboratory of Ocean EngineeringShanghai Jiao Tong UniversityShanghai 200240China Department of Civil Engineering McGill UniversityMontrealQuebec H3A 0C3Canada ZJU-UIUC Institute Zhejiang UniversityHaining 314400China

Urban rail transit (URT) disruptions present considerable challenges due to several factors: i) a high probability of occurrence, arising from facility failures, disasters, and vandalism;ii) substantial negative effects, notably the delay of numerous passengers;iii) an escalating frequency, attributable to the gradual aging of facilities;and iv) severe penalties, including substantial fines for abnormal operation. This article systematically reviews URT disruption management literature from the past decade, categorizing it into pre-disruption and post-disruption measures. The pre-disruption research focuses on reducing the effects of disruptions through network analysis, passenger behavior analysis, resource allocation for protection and backup, and enhancing system resilience. Conversely, post-disruption research concentrates on restoring normal operations through train rescheduling and bus bridging services. The review reveals that while post-disruption strategies are thoroughly explored, pre-disruption research is predominantly analytical, with a scarcity of practical pre-emptive solutions. Moreover, future research should focus more on increasing the interchangeability of transport modes, reinforcing redundancy relationships between URT lines, and innovating post-disruption strategies.

关键词： urban rail transit disruption management resilient network train rescheduling bus bridging services

Decreased AKAP4/PKA signaling pathway in high DFI sperm affects sperm capacitation

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Asian Journal of Andrology 2024年第1期26卷 25-33页

作者： Kun Zhang Xiu-Hua Xu jian Wu Ning Wang gang Li Gui-Min Hao Jin-Feng Cao Hebei Key Laboratory of Infertility and Genetics Department of Reproductive MedicineSecond Hospital of Hebei Medical UniversityShijiazhuang 050000China Department of Reproductive Medicine Affiliated Hospital of Xuzhou Medical UniversityXuzhou 221000China Department of Neurology The 980th Hospital of the People's Liberation Army Joint Logistics Support Force(Bethune International Peace Hospital)Shijiazhuang 050000China.

The sperm DNA fragmentation index(DFI)is a metric used to assess DNA fragmentation within sperm.During in vitro fertilizationembryo transfer(IVF-ET),high sperm DFI can lead to a low fertilization rate,poor embryo development,early miscarriage,etc.A kinase anchoring protein(AKAP)is a scaffold protein that can bind protein kinase A(PKA)to subcellular sites of specific substrates and protects the biophosphorylation reaction.Sperm protein antigen 17(SPA17)can also bind to AKAP.This study intends to explore the reason for the decreased fertilization rate observed in high sperm DFI(H-DFI)patients during IVF-ET.In addition,the study investigates the expression of AKAP,protein kinase A regulatory subunit(PKARIl),and SPA17 between H-DFI and low sperm DFI(L-DFI)patients.SPA17 at the transcriptional level is abnormal,the translational level increases in H-DFI patients,and the expression of AKAP4/PKARIl protein decreases.H,O,has been used to simulate oxidative stress damage to spermatozoa during the formation of sperm DFI.It indicates that H,O,increases the expression of sperm SPA17 protein and suppresses AKAP4/PKARIl protein expression.These processes inhibit sperm capacitation and reduce acrosomal reactions.Embryo culture data and IVF outcomes have been documented.The H-DFI group has a lower fertilization rate.Therefore,the results indicate that the possible causes for the decreased fertilization rate in the H-DFI patients have included loss of sperm AKAP4/PKARIl proteins,blocked sperm capacitation,and reduced occurrence of acrosome reaction.

关键词： AKAP PKA SPA17 sperm capacitation sperm DNA fragmentation index